JPH0217333Y2 - - Google Patents

Description

[Detailed description of the invention] This invention relates to an automatic gas analyzer, and in particular provides an automatic gas analyzer that enables separation analysis by automatic switching of one valve even if there are interfering components in the sample. It is something to do.

The law stipulates that the measurement of odor components in the air must be performed using gas chromatography combined with a low-temperature concentration method for the four components containing sulfur (hydrogen sulfide, methyl mercaptan, methyl sulfide, and methyl disulfide). (Refer to Environment Agency Notification No. 9 of 1972). And as a column used for the analysis, 2
Species (polyphenyl ether and tristianoethoxypropane) are specified, and it is difficult to measure hydrogen sulfide with the former column due to interference from carbonyl sulfide, and with the latter column, methyl sulfide cannot be separated if sulfur dioxide coexists. There was a problem. Therefore, in the past, it was necessary to measure odor components by changing the column used depending on the presence or absence of these interfering components. Moreover, these interfering components are often present in the atmosphere, making the problem even bigger.

This idea was devised in view of these circumstances, and its concrete configuration consists of a sample introduction tube, two carrier gas introduction tubes, two sample collection tubes at both ends of each port of the 12 or more valves, and two
Two different separation columns installed corresponding to one sample collection tube and leading to one detector, a sample suction tube equipped with a pump, and a connection tube are connected at both ends, and both ends are connected by switching valves on 12 or more sides. This is an automatic gas analyzer configured so that each sample collected in a collection tube can be separated and analyzed alternately.

In other words, this invention eliminates interfering components in the sample by configuring two sets of analysis lines consisting of a sample collection tube and a separation column so that they can be used alternately by switching a single valve. Even if one type of separation column exists, the analysis can be performed using either one of the analysis channels.In other words, it is possible to analyze a sample gas that cannot be completely separated using one type of separation column. Furthermore, according to this invention, when a sample in one sample collection tube is being analyzed, a sample can be collected in the other sample collection tube at the same time, thereby making it possible to shorten the analysis time.

This invention will be described in detail below based on the embodiments and conventional examples shown in the figures. Note that this invention is not limited to this.

First, in FIG. 1, an automatic odor analyzer 1 has a sample introduction tube 3, two carrier gas introduction tubes 4 and 5, and two concentration tubes 6 and 7 as sample collection tubes connected to each port a to l of a 12-way valve 2. two different separation columns 9, 10 leading to a detector 8 at both ends;
It is constructed by connecting both ends of a sample suction tube 12 equipped with a pump 11 and a connecting tube 13, respectively.

Here, the separation column 9 uses polyphenyl ether as its packing material, and corresponds to the sample collection tube 6.
The separation column 10 uses triscyanoethoxypropane as a packing material and corresponds to the sample collection tube 7.

Next, the operation of the device 1 having the above configuration will be explained.

First, the 12-way valve 2 is set to the state shown in Fig. 1 (the solid line is in communication), and the collected sample, which has been concentrated (collected) in advance in the concentration tube 6, is sent to the separation column 9 and detector 8 using a carrier gas, and separated. analyse. In this case, as long as the collection tube sample does not contain carbonyl sulfide (more than a predetermined amount), it is possible to separate and analyze each component. During the above analysis, the pump 11 is operated and a certain amount of the sample in the atmosphere is passed through the concentrating tube 7 kept at a low temperature to concentrate and collect the component to be measured.

Next, when the 12-way valve 2 is switched (the dotted line is in communication), the collected sample concentrated and collected in the concentration tube 7 as described above is sent to the separation column 10 and the detector 8 by the carrier gas by heating the concentration tube 7. Separated and analyzed. In this case, as long as sulfur dioxide is not present (more than a predetermined amount), it is possible to separate and analyze each component. The above operations can be repeated alternately and continuously by continuing to switch the 12-way valve.

Note that the concentration tubes 6 and 7 of the above embodiments can also be used in place of mere measuring tubes.

For reference, a conventional odor analyzer 1a is shown in FIG. 2. Of course, here the sample is collected and separated using a pair of concentration tubes 6a and separation column 9.
a, and if the sample contains interfering components corresponding to the packing material of the separation column, analysis cannot be performed. For analysis, another odor analyzer using a different type of separation column (with unobstructed packing material) is required.

[Brief explanation of the drawing]

FIG. 1 is a functional explanatory diagram showing one embodiment of an automatic gas analyzer according to this invention, and FIG. 2 is a diagram corresponding to the previous figure showing a conventional example. 1... Automatic odor analyzer, 2... 12-way valve,
3... Sample introduction tube, 4, 5... Carrier gas introduction tube, 6, 7... Sample collection tube, 8... Detector, 9, 10... Separation column, 11... Pump,
12...Sample suction tube, 13...Connection tube.

Claims (1)

[Scope of utility model registration request] At each port of the 12-way valve or more, a sample introduction tube, two carrier gas introduction tubes, two sample collection tubes are provided at each end, and two different ports are provided corresponding to these two sample collection tubes and lead to one detector. Two separation columns, a sample suction tube equipped with a pump, and a connecting tube are connected at both ends, and each sample collected in both collection tubes can be separated and analyzed alternately by switching valves on 12 or more sides. Automatic gas analyzer.